Paxlovid and Xarelto Interaction Guidelines

Mechanism of Interaction and Risks

Rivaroxaban (Xarelto) is metabolized by CYP3A4 and is a substrate of P-glycoprotein, and when taken with Paxlovid, which contains the strong CYP3A4 inhibitor and P-glycoprotein inhibitor ritonavir, rivaroxaban plasma concentrations can increase by approximately 2.5-fold, leading to increased bleeding risk, as noted by the American College of Cardiology and Chest 1, 2
The combination of Paxlovid and Xarelto can increase rivaroxaban AUC by approximately 150% and Cmax by 70%, according to the European Heart Journal 2

The American College of Cardiology and European Heart Journal classify this interaction as a "red" interaction, meaning the combination is contraindicated or strongly discouraged from use, due to the high risk of bleeding complications 3
Unpredictable anticoagulation effects can occur due to increased rivaroxaban levels, as warned by the European Heart Journal 3

If a patient requires COVID-19 treatment while on Xarelto, consider alternative anticoagulation during Paxlovid treatment, such as temporarily switching to a different anticoagulant with fewer interactions, as suggested by the American College of Cardiology 1
Significant dose reduction of rivaroxaban would be required if the combination must be used, but specific guidance for this scenario is lacking, according to Chest 2

Patients with renal impairment are at even higher risk due to renal dosing considerations for both drugs, as noted by the American College of Cardiology 1